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Factory Hornady 338 ARC 307gr Sub-X vs 300 Blackout 208gr A-Max Ballistics

Hi Ilya,

My distance spec for high confidence varmint/pig with a subsonic AR SBR is 300 yards. I was curious about the new Hornady subsonic 338 ARC down range ballistics at 300 yards, so I visited the Hornady website and did a quick comparison vs the Hornady subsonic 300 Blackout cartridges. This simple comparison follows below.

It would be very interesting to hear about how the down range ballistic performance (accuracy, wind drift and terminal energy) of the best subsonic 6.8 Blackout ammo you have used (or know of) compares to the results below.

The only subsonic Hornady 338 ARC cartridge available at this time seems to use the Sub-X bullet. The subsonic Hornady 300 Blackout cartridge options include the A-Max and the Sub-X. I chose the 300 BO A-Max for the comparison due to it's superior ballistics compared to the Sub-X line. The Sub-X to Sub-X comparison would be obvious, the heavier 338 with slightly better BC and similar internal ballistics would be the obvious choice in all scenarios. Should Hornady produce a 338 ARC with a higher BC bullet the following comparison would likely heavily favor the 338 over the 300.

I used the Hornady website ballistics instead of my Kestrel/AB because it was easy and their 3DOF models are said to be accurate, but I have never used Hornady results in the field so I cannot personally vouch for the accuracy of their website ballistics calculator.

For the long-ish range subsonic scenarios I have experience with, wind drift is generally a major factor. According to Hornady, their subsonic 307 gr 338 cartridge with the Sub-X bullet has a little over half the BC of their subsonic 208 gr 300 Blackout cartridge with the A-Max bullet. This of course results in a bit under 2X the wind drift and a faster loss in terminal energy as range increases for the 338 ARC vs 300 BO. Simplified ballistic charts from the Hornady website calculator are attached below.

The Hornady website ballistic results at 300 yards in 10 mph 90 degree wind are 7.6" drift for the 300 Blackout vs 13.2" for the 338 ARC (74% increase). To put it another way, the wind drift at 300 (400) yards with the 300 BO is the same as the wind drift at 200 (300) yards for the 338 ARC. In the canyons where we often shoot the wind can be very different downrange even at a modest distance of 300 yards, and wind can be considerably higher than 10mph, so this is a significant disadvantage. Evaluating wind in these areas is substantially complicated at night due to lack of high resolution visual down range imagery to determine wind from mirage or foliage.

Further, the increased drag for the 338 ARC results in a reduction in down range energy advantage vs the 300 BO. At the muzzle the 338 has a 57% advantage over the 300 (752 vs 480 ft-lbs) due to not only the larger mass but also a slight increase in velocity, but at 300 yards the advantage drops to 37% (554 vs 402 ft lbs).

A mitigating factor in favor of the 338 could well be the expansion/internal ballistics of the Sub-X vs the A-Max. However, I know of no trusted down range accuracy data for the 338 ARC whereas reliable data is available showing that reasonable accuracy can be achieved with the 300 BO cartridge (as good as about 1.5 MOA at 300 yds). So, at 300 yards the improved expansion and 37% energy advantages for the 338 could be overcome by more accurate shot placement (superior wind performance and inherent accuracy) for the 300, but this is speculation until 338 ARC down range accuracy date is available.

My preliminary conclusion (pending accuracy data for the 338 ARC) is that if your goal is optimum subsonic lethality for varmints and hogs at less than about 150 yards, then the better terminal ballistics of the 338 ARC is probably the way to go, but if you want to reach out to 300 yds+ with the best accuracy in even modestly windy conditions the 300 BO is likely the better choice. As wind and range increase the 300 BO increasingly becomes the preferred choice. Once trusted accuracy data is available for the 338 ARC this preliminary conclusion can be adjusted.

Thanks!

Hornady data for the 338 ARC and 300 Blackout cartridges:

https://www.hornady.com/ammunition/rifle/338-arc-307-gr-sub-x-subsonic#!/

https://www.hornady.com/ammunition/rifle/300-blackout-208-gr-a-max-black#!/

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Every Thanksgiving these last few years I wake up in the morning knowing that this is the year when I will finally get in touch with my sweet, emotional and well meaning inner self and write a truly profoundly heartfelt and warm Happy Thanksgiving message.

That results in several minutes of hopeful soul searching.  Sadly, no matter how deeply I dig, all I come up with is sarcasm, cynicism and a profoundly dark sense of humor.

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I asked ChatGPT and Grok the same exact question: "write a profound happy thanksgiving message for a bunch of patriotic gun nuts"

Here is what I got back:

 

From ChatGPT:

Happy Thanksgiving to Our Fellow Patriots!

As we gather this Thanksgiving, let us give thanks for the blessings of freedom, family, and the great land we call home. We honor the principles that built this nation—strength, resilience, and an unwavering commitment to liberty.

Today, as we carve the turkey and reflect on our blessings, let’s not forget those who have fought to protect our freedoms and those who stand ready to defend them still. It's a time to cherish the bonds of family, the camaraderie of friends, and the power of unity that keeps our American spirit alive.

May your Thanksgiving be filled with the warmth of loved ones, the satisfaction of great food, and maybe a few moments at the range to remind us of the rights and traditions we hold dear.

Here’s to faith in the future, pride in our past, and love for this great nation. From our family to yours—Happy Thanksgiving, and God bless America! 🦃🇺🇸🔫

 

From Grok:

Happy Thanksgiving, fellow patriots and guardians of freedom! On this day of gratitude, let's give thanks for the liberties we cherish, secured by the vigilance and resolve symbolized by each of your steadfast arms. May your gatherings be filled with the warmth of camaraderie, the echoes of liberty, and the assurance that the spirit of America is alive in every one of you. Here's to the Second Amendment, to our shared heritage, and to the unyielding spirit of independence. Enjoy your feast, your fellowship, and keep the flame of freedom burning bright. Happy Thanksgiving!

 

Please put in the commens below which AI message you prefer before reading further.

 

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All that aside, Happy Thanksgiving, Gentlemen!

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Vortex Defender XL
Taking a first, rather extensive, look.

When I visited Vortex back in September, I mentioned that I took a quick look at their new line of Defender red dot sights.


While all three are pretty nice, I thought the largest variant, the XL, stood out.  Despite being relatively compact and having a substantially large window, it seemed to maintain collimation quality very well pretty close to the edges.  That was noteworthy.

Now, I have done a good amount of shooting with it and have some initial thoughts.

The main reason I went with the XL version is two fold.  One is that it looked to have a very large sweetspot.  Another is that while the overall trend with pistol mounted red dot sights is toward enclosed emitter designs, one of the areas where open emitter sights have a distinct advantage is window size.  If you try to make an enclosed emitter RDS with a window this big, it will no longer be practical on a pistol.  Too big.

One of the long running experiments I have going on is an attempt to figure out how much of an issue (for me) is window size.  Many people want the largest window possible.  Others do not hugely care.  In principle, with a larger window size, your follow-up shot can be faster if you enver lost sight of the dot due to the recoil impulse.

In practice, I tend to shoot with rather slim and compact handguns a lot (Glock 43x or 48 most commonly), where the gun moves enough to always lose the dot.  Since you always ahve to reacquire it, the larger window size does not seem to offer all THAT much of an advantage.

Now, I have three similarly sized Glocks (two GLock17 and one 34) with different size red dot sights: Vortex Defender XL, Shield RMS2 and Leupold Deltapoint Micro.  I am going to do some experimentation and see how quickly the gun settles back on target for me with all three.  

The Defender XL is somewhat new for me, so before I do anything with a shot timer, I am just making sure I do some practice with it.

There are several reasons, other than the large window that made me the XL version of the Defender intersting.  I wanted to see if the size will prove to be a hindrance for carry.  I also really liked how they did the battery compartment.  It also comes with the largest dot size of the three: 8MOA.

There are three models: XL, ST and CCW.  XL and ST use DPP footprint.  CCW uses RMS/RMSc footprint.  Parallax and distortion seemed very well corrected on all three.

The window size of the XL is 25.5x23.5mm (WxH). On the ST it is 23x20mm.  On the CCW it is 20x16mm 

In practical terms, the width of the window on the XL is about the same (very slightly narrower)as the width of a full size Glock slide.

The housing, naturally, extends a little bit wider with the widest point being the brightness control buttons on the left and the right.  That makes them very easy to find via the tactile feel.  It also makes me wonder if I will accidentally press them when carrying the gun, so that is something to experiment with.  I do not have any issue concealing a full size pistol, especially now that we are at the beginning of November.  I will keep an eye out for that.  Generally, for a carry gun, I prefer autoadjust brightness, but there are conflicting opinions on that.

In terms of durability, I do not expect any issues.  I know that these were seriously abused during the design phase and the people at Vortex I have talked to do not seem to have any concerns about durability of the Defender red dots.  I am looking at a sample of one, so it is not like I can do anything statistically significant there.

The XL comes with either 5MOA or 8MOA dot size.  ST and CCW are available with 3MOA and 6MOA options.  I have long been a proponent of larger dot sizes in handgun red dot sights.  It seems like competition guys are on board with that (XL is aimed at them to some degree), but why you would want smaller dots on the ST and CCW that are ostensibly aimed at the consumer carry handgun market is not clear to me.  I suspect Vortex is simply giving people what they are asking for even if they are asking for something that makes no sense.

That's the difference, I suppose, between people who criticise stuff for a living (yours truly) and people who have to sell stuff for a living (Vortex).  They have to be very cognizant of what their customers are asking.  I am very curous what the relative sales numbers for different dot sizes are.

The Defender XL I have here came with an 8MOA dot and that is just about perfect.

For an example of what that looks like, here is an 8MOA dot on a 7'x12" plate at 52 yards (note that the red splash to the right of the dot is a reflection off of the camera lens; it is not there when you are using the sight).

There are several reasons I prefer larger dots: they are easy to see at lower relative brightness, they work better with mild astigmatism, they are easy to pick up.  Also, if you are shooting a little further out, it is a little easire to compensate for drop.  For example, if you sight your dot in at 25 yards, with a typical 9mm, you have about 2 inches of drop at 50 yards, about 4 inches of drop at 75 yards and about 10 inches of drop at 100 yards.  On a hundred yard plate, I just place the lower edge of an 8MOA dot on the top edge of the plate.

XL and ST use 2032 batteries.  CCW uses a smaller 1632.  All three have shake awake, so I expect the batteries to last for a while. With all three, the battery is accessible from the top, so you do not have to remove the optic to change batteries. With ST and CCW, the battery cap is simply threaded in, which is uniformly a pain in the ass for many reflex sights out there, including these.  Vortex does give you a tool for that and it sorta works, but I much prefer how they did it with the XL.  Since they had more space to work with, the battery cap is hinged at the front and is released with a simple button.  Not only does it make battery replacement a breeze, it also makes sure you can not get your fingerprint onto the inside fo the lens while messing with the battery.

Shooting with it, my initial impressions are very positive.  Everything worked as it should.  Nothing shifted.  Zeroing in was a breeze, and it stayed zeroed.

Getting on target was VERY quick.  I am not a high speed/low drag kind of guy, so I suspect in the hands of a truly skilled shooter this thing would be blazing.

The gun I have it on is a very modofied version of G17.  The frame started life as a G31 which was the first handgun I ever bought.  I have somewhere between 150k and 200k rounds fired with that frame between the original 357Sig, the later 9mm and also the Advantage Arms 22LR conversion kit.  As you can imagine, all the springs have been replaced more than once.

At some point, I sent it in for a grip reduction, since I do not like the figner grooves very much.  The grip was made slightly smaller and shortened to accept both 17 and 19 magazines.

The trigger I have in it is the Gen3 version of Haley Stregic's Skimmer trigger.

The slide is the first gen Atom from Unity Tactical with the OEM Glock barrel, Lone Wolf striker and extractor.

It is still a Glock, albeit a nice one.

For the side-by-side I am planning to do, the RMS2 sits on a Gen5 Glock 17 that is stock other than sporting a Timney trigger.  Deltapoint Micro is on a bone stock G34. 

Generally, I fully admit that Deltapoint Micro is more appropriate on a slimline G48, but I wanted the guns to be broadly comparable.  Once this test is done, the Micro will go back onto a smaller gun and G34 will be milled for a different optic, probably for Acro footprint.

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NRL Hunter Planning
Rifle Configurations

As I have mentioned previously, I am looking to shoot in a couple of NRL Hunter competitions in 2025.  I have many reasons for that: preparation for the Team Challenge, leading by example (trying to get my kids interested) and simply having fun are all contributing factors.  The "trying to get my kids interested" is what usually gets me a hall pass from my wife, so that one is an integratl part of the reasoning.

One aspect of this whole decision process that needs to be addressed is the almost inevitable paralysis by analysis that every gear junkie is bound to develop when looking at the options.

Given my comparative inexperience and relatively limited shooting skills, I think my best bet is to not overthink it.  Just set up a rifle for the Open Heavy class and go practice.  I intend to shoot 6.5CM, hopefully with factory ammo.  Given that, a ltitle extra weight for controlling recoil and having good information for the second shot after I miss the first one, should be beneficial. 

On the other hand, since there are many ways to win the race for the last place, I could not help myself and tentatively configured rifles (on paper for now) for both Open Heavy and Open Light.  I plan to build them all up exactly as described below and figure out how contorted of a shooting position my aging joints can tolerate with each one.

The idea, for now, was to simply look at what I have and play with different configurations.

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